The invention concerns a method for determining the position of a chip card in a card reading device, in cases where the chip is arranged eccentrically in the card, as well as a device for carrying out such a method.
If a chip card of a type conventional today, which has no magnetic readable strip or whose magnetic readable strip is not written on, is inserted into a card reader with a chip card contact station, the chip card can take four different orientations relative to the chip contact station. Nevertheless, only one orientation leads to a successful contacting of the chip, since the chip card contact station can only make contact with one area of the chip card. Since the user generally cannot determine where the contact elements of the reader are located, he often must make several insertion attempts, until he finds out in which orientation he has to insert the chip card into the card reader to assure a successful contacting.
In the case of cards with a magnet strip it is already known to provide means for predetermining the magnetic track. Thereby insertion of non-standard objects and especially a manipulation of the reading device is inhibited. With this magnet track pre-recognition, it can further be determined among other things that the actual insertion orientation of the card is not correct. It cannot however be determined in which orientation the card is actually located and how the user must change the orientation of the card in order to make possible a chip card contacting.
The invention has as its basic object the provision of a method of the aforementioned kind in which the actual orientation of a card can be determined and as the case may be, it can decided in which way the orientation of the card has to be changed in order to correctly insert it into the card reader.
The above object is solved in accordance with the invention in that at the four possible positions which a chip of a chip card inserted into the card reading device can take, the presence of the chip contact surface is determined.
With the method of the invention it is therefore not only determined that a card has been inserted falsely orientated into the card reader but it is also determined in which orientation the chip is actually located. Therefore, it is possible to indicate the orientation of the chip and/or of the chip card and to give the user a report on how the user is to correctly insert the card. Further there exists the possibility of so changing the position of the card or the position of the contact elements of the reader that a correct contacting of the chip is possible.
The presence of the chip contact surface can be determined inductively, capacitively or by a resistance measurement through direct contacting of the chip contact surface.
For the carrying out of the previously described method an apparatus is proposed for determining the orientation of a chip card in the card receiver of a card reader by having a sensor located opposite each of the four possible positions which the chip can take when the card is inserted into the card reader to a test position, with each of the sensors being capable of determining the presence of the chip contact surface and being connected with an evaluation circuit. The test position can correspond to the card reading position.
In a first embodiment, the sensors are each formed to provide an inductive recognition of the presence of the chip contact surface. In this case each sensor can include a pair of coils with one coil being a transmitting coil located on one side of the chip card receiver and with the other coil being a detecting coil located on the other side of the chip card receiver, which two coils are connected to one another so as to be in series resonance with respect to an exciting frequency. The alternating voltage applied to the involved transmission coil induces an alternating voltage across the detection coil. If now the chip contact surface comes between such a coil pair it reduces for that sensor the value of the detected alternating voltage. By comparison of the values detected by the four sensors it can be determined at which of the sensors the chip contact surface lies. Therefore, the orientation of the chip card in the card receiver can be clearly determined.
In another embodiment, the sensors are each formed to provide a resistance measurement. This can be accomplished in that each sensor has a pair of contact pins which are adjustable in the direction toward the chip card so that the contact pins can be brought into galvanic contact with the chip contact surface. The resistance values determined at the four positions are again compared with one another in the evaluation circuit in order to identify the position of the chip and thereby the orientation of the chip card.
Finally there exists the possibility that the sensors can each be formed to carry out a capacitative recognition of the presence of the chip contact surface, in which case for example each sensor has a capacitor with capacitor surfaces arranged on opposite sides of the card receiver. If now the chip card is inserted between the capacitor plates, the capacitance of the involved capacitor is changed by the inserted card material. At the position of the chip contact surface this change is, however, the highest.
Advantageously, the evaluation circuit is connected with an indicator device to indicate to the user the orientation of the card or the measures needed to be taken to bring the card into its correct orientation.
As the case may be, the evaluation circuit can also be connected with a position correcting device in order to either change the position of the card in the card receiver or the position of the contact elements relative to the card in dependence on the results reported by the sensors.
Further features and advantages of the invention will be apparent from the following description which in connection with the accompanying drawings explain the invention by way of exemplary embodiments. The drawings are: